Electric switch



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Patented Nov. 29, 1949 ELECTRIC SWITCH John R. Caldwell, Hampton, OlanRichardson, Atlanta, and Thomas E. Curtis, Hampton, 6a., assignors toSouthern States Equipment Corporation, a corporation of GeorgiaApplication January 10, 1947, Serial No. 721,184

3 Claims.

This invention relates to electric switches in which a hingedly mountedswitch arm is moved into' and out of engagement with a contact spacedaway from the hinge mounting, and in which the pressure between theswitch arm and the contact is increased after the-switch arm hascompleted its arcuate motion in closing. More particularly it relates tothe type of switch in which this increased pressure is produced by apartial rotation of the switch arm about its longitudinal axis.

Referring to the drawings, Fig. 1 shows in reduced scale a single poleof one type of switch embodying this invention; Fig. 2 is an enlargedside view of the hinge portions of the switch; Fig. 3 is a top view ofthe parts shown in Fig. 2; Fig. 4 is a sectional view along the plane4-4 when the switch arm is midway in iii rotative travel; Fig. 5 is alongitudinal view along the section 5-5; Fig. 6 is an end view of theswitch arm and the contact: Fig. 1 is a diagram explaining one part ofthe operating motions of the switch; Fig. 8 is a top view of a modifiedarrangement of the operating member; and Fig. 9 shows a detail.

The base I supports two stationary insulators 2, 3 and one rotativeinsulator 4 which is controlled by crank 5. The crank l is integral withthe rotative insulator unit 4. The hinge base I is secured to insulator3 and it also serves as e a steady bearing for the top of insulator unit4.

Line 8 is connected to hinge base I, and line 8' is electricallyconnected to contact l3. Switcharm structure 9 is hinged on hinge pivotl0 and it includes the switch arm II which is rotative about its ownlongitudinal axis. Switch arm II has a flattened end l2 which engageswith contact l3. Rocker I4 is mounted on hinge base 1 by rocker pivot IIwhich is parallel with hinge pivot I0, connecting rod I6 is held by auniversal joint to crank 6, and, a second universal joint and swingpivot I! hold connecting rod IE to rocker I4. Swing pivot II alsocarries two curved links l8, l9 which are connected by diagonal pivot 20to terminal bearing member 2| which is integral with and a part ofrotative switch arm II. The switch-arm structure 9 also includes thehinge member 22 which is mounted on the hinge base I by hinge pivots l0,l0, and which provides the trunnion in which terminal bearing member 2|rotates.

Fig. '7 is a diagram showing how switch arm ll is-rotated by motion ofrocker l4 and links I8, I9. When the switch is fully closed swing pivotI! is at position indicated by IIa and the link I! is indicated by Na,with the near end of diagonal pivot 20 being at a. The location ofrocker pivot I5 is shown at lia. Link i8 occupies the position indicatedby l8a, with the far end of pivot 20 being at location c. As rocker i4is moved so that swing pivot I1 is moved to position llb, the link l8takes position l8b and link l9 takes position lab. In other words thenear end of pivot 20 is raised to b and the far end of pivot 20 islowered to d. This places link IS in tension and link It in compressionand as they are on opposite sides of switch arm I I they rotate switcharm ll without otherwise changing its location. Fig. 8 is a plan viewshowing how the two links l8, is can be replaced by a single bifurcatedmember 23 which is mounted on diagonal pivot 20 and on swing pivot I!without altering the locations of saidpivots. In this case swing pivotll passes through the single eye 24 which is integral with 23, and whichfits within the clevis 25, which is part of the universal jointconnection to connecting rod It. In this case, the single 23, 24, 22 isrotatable about the straight diagonal pivot 20, the eye 24 tending tomove at right angles to axis of pivot 20. However, the rocker l4 forcesswing pivot ll to travel at right angles to axis of pivot I5. Theresultant is the same as with two separate links, namely to raise oneend of pivot 20 and lower the other end, thereby causing rotation ofswitch arm II. There are slight discrepancies in the travel of thevarious members, and when two links such as l8, it are used, properclearances are allowed at each end of each link to prevent binding. Whena single bifurcated link is used such as 23, 24, 23 all the clearancefor these slight discrepancies is provided between eye 24, clevis 25 andswing pivot l'l. As shown in Fig. 9, the link 23, 24, 23 may be replacedby the swivelled members 23', 24', 24" the swivelled eye 24 replacingthe rigid eye 24. In such arrangements,

no extra clearance is needed between eye 24' and clevis 25.

Operation is as follows: Assuming the switch to be fully closed, thefiat end l2 of arm H is horizontal and is in heavy pressure engagementwith contact members l3, l3; Hinge members are as shown in Fig. 2. Whencrank 5 is turned, connecting rod l6 moves rocker l4 counter-clockwisemoving swing pivot 11 from position lie to "D. This places link I! undertensionand link It under compression. This partially rotates switch armll so that end I2 is released from heavy pressure against contact l3,l3. Further motion of crank it moves pivot l'l so that the 3 plane whichincludes the axes of pivots l1 and i5 is past the locations 0 and d.Further counterclockwise motion of rocker i4 changes the stress on linkIt from compression to tension so that links l8 and I9 are both intension and this lifts the diagonal pivot 20 and so raises switch arm llthrough its operating plane, which is normal to the axis of pivots l0,Hi, until the switch arm ultimately reaches its fully open verticalposition. Since the axes of pivots l0, l8 and ii are parallel, themotion of swing pivot I! is likewise parallel with the operating plane.

through which switch arm ll swings.

The reverse motions close the switch and rotate arm ll so that end I! isagain horizontal as shown in Fig. 6 and the switch is fully closed.

If it should be desired, diagonal pivot 20 could be replaced by twoseparate pivots which need nothave the same axes. Instead of pivot l1serving as the connection with connecting rod IS, a second pivot couldbe provided adjacent to pivot I I. And various other changes might bemade by one familiar with the art without departing from the spirit andpurpose of this invention.

We claim:

1. In an electric switch, an insulated contact, and spaced away from itan insulated hinge base carrying a hinge pivot, a switch arm mounted onsaid hinge pivot to swing through its operating plane from its openposition to its closed switch location and into engagement withsaidcontact and also rotatable about its longitudinal axis when at itsclosed location, a rocker pivot mounted in a fixed position on saidhinge base spaced from and parallel with said hinge pivot. a rockermounted on said rocker pivot, a swing pivot in the swing end of saidrocker and movable only in a fixed are parallel with said operatingplane, and linkage directly connecting the swing pivot with therotatable switch arm to rotate the switch arm when at its closedlocation, together with means to move the rocker in one continuousmotion and so operate the switch from fully closed to fully openposition.

2. In an electric switch an insulated contact and spaced away from it aninsulated hinge base carrying a hinge pivot, a switch arm mounted onsaid hinge pivot to swing in its operating plane into and out ofengagement with said contact and also rotatable about its ownlongitudinal axis when at its closed switch location, a rocker pivotalso mounted on said hinge base and a rocker mounted on said rockerpivot, with its swing end movable only in a fixed are about the rockerpivot and parallel with said operating plane, two links pivotallyconnected to the swing end of the rocker and with their other endspivotally connected with the rotatable switch arm at substantiallydiflerent distances from the hinge pivot and operable by motion of therocker to rotate the switch arm about its longitudinal axis when theswitch arm is at its closed location.

3. In an electric switch, an insulated contact and in spaced relation toit an insulated hinge base carrying a hinge pivot, a switch arm mountedon said hinge pivot to swing in its operating plane from its openposition to its closed switch location and into engagement with saidcontact and also rotatable about its own longitudinal axis to vary itsengagement pressure with said contact. a swing pivot movably supportedupon said hinge base and movable only in a fixed are parallel with saidoperating plane, two links pivotally connected with said swing pivot andwith their other ends pivotally connected to opposite sides of saidswitch arm at susbtantially diflerent distances from said hinge pivotand operable to rotate the switch arm when at its closed location,together with operating members to move the swing pivot and thereby tooperate the switch.

JOHN R. CALDWELL. OLAN RICHARDSON. THOMAS E. CURTIS.

REFERENCES CITED The following references are of record in the tile 01'this patent:

UNITED STATES PATENTS Number Name Date 1,560,998 Koppitz Nov. 10, 19252,276,257 Caldwell Mar. 10, 1942 2,303,119 Froland Nov. 24, 19422,328,171 Schwager et a1 Aug. 31, 1943

